This invention relates to a method and a device for fabricating an insulated joint between a pair of end abutting rail sections of a railroad track.
For train safety purposes, it is frequently necessary to divide the railroad track into insulated track sections for which purpose insulated joints are fabricated into the tracks.
There are basically three different known types of insulated joints. For example, in an insulated adhesive butt joint, a two-component adhesive is thickly applied to the metal-smooth back side of the fishplate and a layer of glass fiber fabric is set into the moist adhesive. Then, an insulation lining is thickly coated on its inner surface with an adhesive and is placed on the layer of glass fiber fabric over the fishplate. After the insulation lining has been thickly coated with adhesive also on its outer surface and a layer of glass fiber fabric has been applied thereto, the smooth fish surfaces of the abutting rail sections are thickly coated with adhesive and the pretreated fishplates are then disposed against the opposed coated fish surfaces and are mounted in place with the use of fasteners.
In another known, insulated, steel fishplate butt joint arrangement, the fish surfaces in the area of the insulated joint are the protective casings of the insulated steel fishplates are ground metallically smooth and a mortar mass mixed from resin and hardener is applied with a wedge shaped spatula to the dry inner surfaces of the insulated steel fishplates, is compressed and then profiled. The fishplate screws are then inserted through aligned bores in the fishplates and webs of the abutting rail sections and are thereafter tightened.
In still another known embodiment of an insulated rail joint, an insulation cuff is inserted between each fishplate and the rail after the rail sections and fishplates have been sequentially heated. Such a cuff consists of a layer of fabric and a heat-activatable adhesive which is activated when the joint is heated to a predetermined temperature for approximately 20 minutes to thereby constitute an adhesive joint.
This latter type joint has the particular advantage relative to other known joints in that the two-component adhesive which is used, having a certain pot life, need not be made in situ, but is readily available as a cuff and need merely be heated in order to be activated. However, fabrication of this insulated rail joint requires the rail sections and the fishplate surfaces which are to be adhered together to be cleaned, followed by the heating to a predetermined temperature of first the rail sections and then the fishplates. Then, immediately after the cuff is placed into the space between the fishplate and the rail, the fishplate is inserted against the fish surface and screws are inserted through the aligned bore holes. The fishplate must then be held stationary on one side by the operator. Then, the cuff is introduced on the opposite side of the rail between the fish surfaces and the fishplate and the fishplate is moved onto the screw bolts until this opposed fishplate also bears against the fish surfaces.
However, a disadvantage in this fabrication technique is that it is relatively time consuming because the rail sections and the fishplates must be heated one after the other. It also requires additional personnel since one workman is needed to steadily hold one fishplate in place while another workman must install the opposed fishplate over the screw bolts from the opposite side. This operation is rendered all the more difficult because of the applied heating temperature of about 200.degree. C.